Before September 11 2001, the world was by no means a peaceful place. Violence happened, wars happened - and yes, terrorism happened. Al-Qaeda was already a known presence in the 1990s, but until the planes hit those towers, nobody could truly fathom how divisive a single event could be.
Nearly 3,000 people were killed in the attack. Four planes, hijacked by the terrorist group, crashed into the World Trade Centre skyscrapers, the Pentagon, and a field near Shanksville in Pennsylvania, sending shockwaves of fear and anxiety around the globe. A further 6,000 people were injured as a direct result of the event, and over $10 billion worth of damage to property and infrastructure was incurred.
So how has the world changed since then?
For starters, we are far more cautious now. The World Trade Center was actually the target of a previous terrorist attack in 1993, but the reaction to it was nowhere near as extreme. Despite six people being killed in the attack, and a further thousand sustaining injuries, there was not a huge response in terms of adapting security measures.
By contrast, after 9/11, the TSA and Department of Homeland Security were created in order to detect, monitor and quash any further potential terror attacks. Security in airports around the world changed, too - and it's almost impossible to travel by plane without some reminder of what happened 16 years ago. Limits on liquids allowed in hand luggage, rigorous security pat-downs and body-scans, strict enforcement on passport and identity checks; all of it came about as a result of the September 11 attacks.
We're also more aggressive than before. The War on Terror, as it is commonly known, was announced by former President George W. Bush just days after the USA was hit. The wars in Afghanistan and Iraq came about as a direct result of this - the former of which is still ongoing.
The rise of ISIS and other terror organisations since 2001 have further fuelled another result of the 9/11 attacks: we have become more hateful. Racism - and more specifically Islamophobia - spiked in the US, as well as in other nations around the world. Even this year, President Trump's Muslim ban could be directly linked to the attacks sixteen years ago - despite many of the countries on the no-fly list having no involvement in the attack.
Today, on the sixteenth anniversary of the tragedy, President
Donald Trump - a New Yorker himself - is due to mark the anniversary for the first time as the leader of the USA. Services will also take place at The Pentagon and Shanksville, where construction of a memorial tower is still underway to commemorate the 33 passengers and seven crew members who sadly died there.
Ground Zero is also in the midst of ongoing construction works, too. A third office tower is due to open next year, as well as a Greek Orthodox church. A $250 million performing arts center is being built, too, with the aim to turn the site into something more positive and productive.
9/11 is undoubtedly the most pivotal event of the 21st century. Many of the responses to it have been negative - but a great deal of them have been necessary, too, and the implementation of stricter security protocols have certainly saved thousands of lives since their formation.
The September 11 attacks will always remain in the memories of all those who were alive to witness them. Now we must use those memories to build a better world.
